/** @file

  Copyright (c) 2017-2018, Arm Limited. All rights reserved.

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

  System Control and Management Interface V1.0
    http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/
    DEN0056A_System_Control_and_Management_Interface.pdf
**/

#ifndef ARM_SCMI_CLOCK_PROTOCOL_H_
#define ARM_SCMI_CLOCK_PROTOCOL_H_

#include <Protocol/ArmScmi.h>

#define ARM_SCMI_CLOCK_PROTOCOL_GUID { \
  0x91ce67a8, 0xe0aa, 0x4012, {0xb9, 0x9f, 0xb6, 0xfc, 0xf3, 0x4, 0x8e, 0xaa} \
  }

extern EFI_GUID gArmScmiClockProtocolGuid;

// Message Type for clock management protocol.
typedef enum {
  SCMI_MESSAGE_ID_CLOCK_ATTRIBUTES     = 0x3,
  SCMI_MESSAGE_ID_CLOCK_DESCRIBE_RATES = 0x4,
  SCMI_MESSAGE_ID_CLOCK_RATE_SET       = 0x5,
  SCMI_MESSAGE_ID_CLOCK_RATE_GET       = 0x6,
  SCMI_MESSAGE_ID_CLOCK_CONFIG_SET     = 0x7
} SCMI_MESSAGE_ID_CLOCK;

typedef enum {
  SCMI_CLOCK_RATE_FORMAT_DISCRETE, // Non-linear range.
  SCMI_CLOCK_RATE_FORMAT_LINEAR    // Linear range.
} SCMI_CLOCK_RATE_FORMAT;

// Clock management protocol version.
#define SCMI_CLOCK_PROTOCOL_VERSION 0x10000

#define SCMI_CLOCK_PROTOCOL_PENDING_ASYNC_RATES_MASK      0xFFU
#define SCMI_CLOCK_PROTOCOL_PENDING_ASYNC_RATES_SHIFT     16
#define SCMI_CLOCK_PROTOCOL_NUM_CLOCKS_MASK               0xFFFFU

/** Total number of pending asynchronous clock rates changes
  supported by the SCP, Attr Bits[23:16]
*/
#define SCMI_CLOCK_PROTOCOL_MAX_ASYNC_CLK_RATES(Attr) (                       \
                  (Attr >> SCMI_CLOCK_PROTOCOL_PENDING_ASYNC_RATES_SHIFT) &&  \
                   SCMI_CLOCK_PROTOCOL_PENDING_ASYNC_RATES_MASK)

// Total of clock devices supported by the SCP, Attr Bits[15:0]
#define SCMI_CLOCK_PROTOCOL_TOTAL_CLKS(Attr) (Attr & SCMI_CLOCK_PROTOCOL_NUM_CLOCKS_MASK)

#pragma pack(1)

/* Depending on the format (linear/non-linear) supported by a clock device
   either Rate or Min/Max/Step triplet is valid.
*/
typedef struct {
  union {
  UINT64 Min;
  UINT64 Rate;
  };
  UINT64 Max;
  UINT64 Step;
} SCMI_CLOCK_RATE;

#pragma pack()

typedef struct _SCMI_CLOCK_PROTOCOL SCMI_CLOCK_PROTOCOL;

// Protocol Interface functions.

/** Return version of the clock management protocol supported by SCP firmware.

  @param[in]  This     A Pointer to SCMI_CLOCK_PROTOCOL Instance.

  @param[out] Version  Version of the supported SCMI Clock management protocol.

  @retval EFI_SUCCESS       The version is returned.
  @retval EFI_DEVICE_ERROR  SCP returns an SCMI error.
  @retval !(EFI_SUCCESS)    Other errors.
**/
typedef
EFI_STATUS
(EFIAPI *SCMI_CLOCK_GET_VERSION) (
  IN  SCMI_CLOCK_PROTOCOL  *This,
  OUT UINT32               *Version
  );

/** Return total number of clock devices supported by the clock management
   protocol.

  @param[in]  This         A Pointer to SCMI_CLOCK_PROTOCOL Instance.

  @param[out] TotalClocks  Total number of clocks supported.

  @retval EFI_SUCCESS       Total number of clocks supported is returned.
  @retval EFI_DEVICE_ERROR  SCP returns an SCMI error.
  @retval !(EFI_SUCCESS)    Other errors.
**/
typedef
EFI_STATUS
(EFIAPI *SCMI_CLOCK_GET_TOTAL_CLOCKS) (
  IN  SCMI_CLOCK_PROTOCOL  *This,
  OUT UINT32               *TotalClocks
  );

/** Return attributes of a clock device.

  @param[in]  This        A Pointer to SCMI_CLOCK_PROTOCOL Instance.
  @param[in]  ClockId     Identifier for the clock device.

  @param[out] Enabled         If TRUE, the clock device is enabled.
  @param[out] ClockAsciiName  A NULL terminated ASCII string with the clock
                              name, of up to 16 bytes.

  @retval EFI_SUCCESS          Clock device attributes are returned.
  @retval EFI_DEVICE_ERROR     SCP returns an SCMI error.
  @retval !(EFI_SUCCESS)       Other errors.
**/
typedef
EFI_STATUS
(EFIAPI *SCMI_CLOCK_GET_CLOCK_ATTRIBUTES) (
  IN  SCMI_CLOCK_PROTOCOL  *This,
  IN  UINT32               ClockId,
  OUT BOOLEAN              *Enabled,
  OUT CHAR8                *ClockAsciiName
  );

/** Return list of rates supported by a given clock device.

  @param[in] This        A pointer to SCMI_CLOCK_PROTOCOL Instance.
  @param[in] ClockId     Identifier for the clock device.

  @param[out] Format      SCMI_CLOCK_RATE_FORMAT_DISCRETE: Clock device
                          supports range of clock rates which are non-linear.

                          SCMI_CLOCK_RATE_FORMAT_LINEAR: Clock device supports
                          range of linear clock rates from Min to Max in steps.

  @param[out] TotalRates  Total number of rates.

  @param[in,out] RateArraySize  Size of the RateArray.

  @param[out] RateArray   List of clock rates.

  @retval EFI_SUCCESS          List of clock rates are returned.
  @retval EFI_DEVICE_ERROR     SCP returns an SCMI error.
  @retval EFI_BUFFER_TOO_SMALL RateArraySize is too small for the result.
                               It has been updated to the size needed.
  @retval !(EFI_SUCCESS)       Other errors.
**/
typedef
EFI_STATUS
(EFIAPI *SCMI_CLOCK_DESCRIBE_RATES) (
  IN     SCMI_CLOCK_PROTOCOL     *This,
  IN     UINT32                   ClockId,
  OUT    SCMI_CLOCK_RATE_FORMAT  *Format,
  OUT    UINT32                  *TotalRates,
  IN OUT UINT32                  *RateArraySize,
  OUT    SCMI_CLOCK_RATE         *RateArray
  );

/** Get clock rate.

  @param[in]  This        A Pointer to SCMI_CLOCK_PROTOCOL Instance.
  @param[in]  ClockId     Identifier for the clock device.

  @param[out]  Rate       Clock rate.

  @retval EFI_SUCCESS          Clock rate is returned.
  @retval EFI_DEVICE_ERROR     SCP returns an SCMI error.
  @retval !(EFI_SUCCESS)       Other errors.
**/
typedef
EFI_STATUS
(EFIAPI *SCMI_CLOCK_RATE_GET) (
  IN  SCMI_CLOCK_PROTOCOL  *This,
  IN  UINT32               ClockId,
  OUT UINT64               *Rate
  );

/** Set clock rate.

  @param[in]  This        A Pointer to SCMI_CLOCK_PROTOCOL Instance.
  @param[in]  ClockId     Identifier for the clock device.
  @param[in]  Rate        Clock rate.

  @retval EFI_SUCCESS          Clock rate set success.
  @retval EFI_DEVICE_ERROR     SCP returns an SCMI error.
  @retval !(EFI_SUCCESS)       Other errors.
**/
typedef
EFI_STATUS
(EFIAPI *SCMI_CLOCK_RATE_SET) (
  IN SCMI_CLOCK_PROTOCOL  *This,
  IN UINT32               ClockId,
  IN UINT64               Rate
  );

typedef struct _SCMI_CLOCK_PROTOCOL {
  SCMI_CLOCK_GET_VERSION GetVersion;
  SCMI_CLOCK_GET_TOTAL_CLOCKS GetTotalClocks;
  SCMI_CLOCK_GET_CLOCK_ATTRIBUTES GetClockAttributes;
  SCMI_CLOCK_DESCRIBE_RATES DescribeRates;
  SCMI_CLOCK_RATE_GET RateGet;
  SCMI_CLOCK_RATE_SET RateSet;
} SCMI_CLOCK_PROTOCOL;

#endif /* ARM_SCMI_CLOCK_PROTOCOL_H_ */

